For the price of a pawn, Duda has managed to keep the opponent's king in the danger zone, but Vidit is quickly running toward safety. The price of every move increases drastically.
18. d4e5 What else $1 The queen was removed to gain this one tempo, which opens up the black king. 18... a5a4 Vidit follows the principled line. 19. e2g4  19... h5g4  20. e5d6 